An analysis of 24 autopsied cases with supramitral rings

Abstract

The supramitral ring is a rare congenital malformation formed by presence of a ridge of connective tissue, usually attached at or above the mitral annulus. The incidence and clinical presentation is highly variable due to difficulty in diagnosis. A review of autopsied congenital heart diseases at our institute over a 17-year-period revealed 24 cases of supramitral ring. These were classified with respect to the morphology of the ridge and the presence of associated cardiac lesions. The ring was found in 1.5% of the autopsied specimens of congenitally malformed hearts, and in 37.5% of those with obstructed left-sided inflow tracts. The majority of the specimens came from children (79.2%). A clinical diagnosis had been made in only two. In one-third of the cases, the ring was associated with incomplete Shone's complex. Varied anomalies were seen in others, chiefly ventricular septal defects. An interesting association was the presence of rheumatic mitral valvar disease, found in 3 cases. There was no difference in the completeness or width of the supramitral ridge in the hearts from those with or without Shone's complex. Circumferential rings were fleshy and stenosing, while incomplete rings had variable locations and stenosis. The presence of a supramitral ring may be underestimated due to association with other cardiac anomalies, both congenital and acquired. Since the ridge need not always produce stenosis, the correct designation would be simply a supramitral ring.

Surgical strategies and outcomes in patients with supra-annular mitral ring: a single-institution experience☆

“…In our series, only two patients had isolated SMR (8%). Yaideeswar and colleagues [15] identified associated rheumatic MV abnormalities in three cases and there exists a possibility for the ridge to develop as a postinflammatory phenomenon.…”

Mid-Term Results of Congenital Supravalvar Mitral Ring Resection

“…Supravalvar mitral ring . In their analysis of 1633 cases, Vaideeswar and colleagues reported that SMR had an incidence of 1.5% among all CHDs, which also accounted for 37.5% of those with an obstruction in the left‐side inflow tract …”

“…In some cases, adhesion of the membrane to the valvar tissue may impair the opening of the leaflets; the ring may protrude into the mitral valve and cause obstruction . This congenital cardiac pathology is usually associated with other cardiac abnormalities and is described as one of the four components of the Shone's complex …”

“…2 This congenital cardiac pathology is usually associated with other cardiac abnormalities and is described as one of the four components of the Shone's complex. 3,4 In this report, we present the mid-term results of our patients with surgical supravalvar mitral ring resection and review the literature on management of this congenital anomaly.…”

Shone variant with large eustachian valve: implication for repair and heart transplantation

“…A significant number of cases are atypical with not all the components of the complex, and in those cases, the prognosis is better. Some cases are even diagnosed in adulthood [3][4][5]. For the most severe cases, the prognosis continues to be poor [6][7][8][9].…”